Marchbank injury a blow to Carlton's defensive stocks

Carlton's tall-defender woes have worsened with the club revealing that centre half-back Caleb Marchbank is expected to miss at least a month with an an ankle injury.

Marchbank, who had impressed by averaging 18 disposals and nine spoils across the opening two rounds, hurt his ankle when he landed awkwardly while being tackled by Ben Crocker in last Friday's loss to Collingwood.

"There's not a whole lot of damage there. but he'll still be out for around a month,'' Carlton head of football Andrew McKay said.

Carlton take on North Melbourne in Hobart on Saturday. The Roos, who have won the past three matches between the two teams, have imposing marking options forward, with Ben Brown, Jarrad Waite and skipper Jack Ziebell.